1. Field of the Invention
The present invention generally relates to methods and apparatus for hermetically sealing opto-electronic devices. More particularly, the present invention relates to a system for hermetically sealing photonic devices such as vertical cavity surface emitting lasers (VCSELs), photo-detectors, and the like.
2. Description of the Related Art
The use of photonic devices, such as VCSELs and photo-detectors, is becoming increasingly popular in the communications and electronics industry. Briefly, a VCSEL is a semiconductor laser which typically emits light normal to the surface to which it is mounted, and a photo-detector typically receives the light transmitted by the VCSEL. In general, photonic devices are used for transmitting data in the form of pulses of light in optical fibers such as in forming data links for parallel transmission and network computing. Photonic devices are particularly desirable as they can be processed, tested and screened on wafers, which facilitates high yield and thus low cost production.
However, the performance of photonic devices, has been found to be subject to environmental contaminants such as dust, moisture, and industrial chemicals. For example, moisture can damage or seriously degrade the performance of photonic devices. Therefore, it is desirable to hermetically seal photonic devices to protect them from dust, moisture, and other environmental contaminants.
A conventional method of sealing photonic devices involves covering the photonic devices in epoxy. As moisture can still penetrate the epoxy seal, however, a true hermetic seal is not formed. Other conventional methods of hermetically sealing photonic devices typically encase the photonic devices inside of TO can packages, which are typically Kovar metal cans with optical windows, and seals the packages with weld or solder. In generally, however, only one photonic device at a time can be hermetically sealed using these methods. Accordingly, these methods are generally costly and time intensive.
The present invention relates to hermetically sealing photonic devices such as vertical cavity surface emitting lasers (VCSELs), photo-detectors, and the like. In accordance with an exemplary embodiment of the present invention, a photonic device is mounted on a substrate material and sealed in a flexible hermetic seal. In one configuration, the photonic device is configured to emit or to receive light through the substrate material. In this configuration, the photonic device is covered with an adhesive layer and a metal layer deposited onto the adhesive layer. In another configuration, the photonic device is configured to emit or to receive light in a direction substantially vertically upward from the substrate material. In this configuration, a cover is placed over the photonic device, then the cover is hermetically sealed to the substrate material with an adhesive layer and a metal layer deposited onto the adhesive layer. In both configurations, the photonic devices are hermetically sealed according to various aspects of the invention on the substrate material without using a separate package. Accordingly, any number of hermetically sealed photonic device submounts can be mass produced on wafers using the present invention.